1. Field of the Invention
The present invention relates to a driving circuit and related driving method, and more particularly, to a driving circuit and driving method operating at multiple operating voltages.
2. Description of the Prior Art
FIG. 1 illustrates a block diagram of a driving circuit 100 in the prior art. As shown in FIG. 1, the driving circuit 100 comprises driving modules 101 and 103. Driving currents I1 and I2 are generated and outputted to a connection pad 107 according to an input signal DIN. The driving circuit 100 includes an operating voltage receiving end 106 to receive operating voltage VOP for the driving modules 101 and 103. The driving circuit 100 may be used to drive various electronics. Therefore the driving modules 101 and 103 are usually designed for various electronics such that one of them is adapted to operate in higher voltage and the other is adapted to operate in lower voltage. Furthermore, the operating voltage VOP can be varied depending on the electronic device in which the driving modules are disposed. For example, when the driving circuit 100 is used to drive LPDDR1 (low power double data rate memory 1 applicable to mobile devices), the operating voltage VOP is 1.8V. When the driving circuit 100 is used to drive LPDDR2 (low power double data rate memory 2 applicable to mobile devices), the operating voltage VOP is 1.2V. Assuming the driving module 101 is the component operating in higher voltage, e.g., 1.8V. And the driving module 103 is the component operating in lower voltage, e.g., 1.2V.
In operations in the prior art, the driving module 101 is deactivated and the driving module 103 is activated if the operating voltage VOP is 1.2V. Conversely, if the operating voltage VOP is 1.8V, the driving module 101 is activated and the driving module 103 is deactivated to self-protect from higher voltage. However, the input signal DIN is not fixed and varies from time to time. As a result, the driving module 103 cannot be fully deactivated and some current is leaked. If realizing the driving module 103 by elements capable of operating in higher voltage, circuit size would be increased accordingly.
From the above it is clear that prior art still has shortcomings. Thus, there is a need in the industry for a novel technique that solves these problems.